


Transformation

by OnlyInAutumn



Category: From Dusk Till Dawn: The Series
Genre: Explicit Sexual Content, F/M
Language: English
Status: Completed
Published: 2016-09-30
Updated: 2016-10-05
Packaged: 2018-08-18 15:22:18
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 5,364
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8166610
Author URL: https://archiveofourown.org/users/OnlyInAutumn/pseuds/OnlyInAutumn
Summary: Richie turned Kate into a culebra at the blood well, and as a result of a guilty conscience, Seth offers himself up to her as Kate's personal blood source. As it turns out, Seth doesn't mind so much. Sexual tension and pining ensues.





	1. A New Sort of Feeling

“You what?!”

Seth’s voice echoed so loud that the he thought that it might puncture his own eardrum, voice filled with anger and disgust.

“I turned her,” Richie said calmly again, trying to keep his face straight. After a moment of watching Seth shake his head in revulsion for his brother, he pointed a finger against his chest and rambled on with his defense. “I had to! There was no other option.”

“No other option,” Seth muttered in doubt, fake smirk present before it was wiped off by his hands running over his face. “Fuck.”

And to think, he had thought things could not have gotten any worse.

Spoiler alert, they did.

“Scott wouldn’t do it. I had to.”

It made him enraged again, voice shaky from anger. “Let me guess. Scott wouldn’t turn her because she didn’t want to she turned.”

Richie’s eyes fell to the floor in something similar to shame, though not entirely since he was under the impression he had done the right thing. “It doesn’t matter now. What’s done is done. She’s like me now.”

With the way he was pacing back and forth, it was all too obvious that Seth was losing his mind. _She’s like me now._ One of the bloodsuckers. A fear of his had come true after all.

“Listen.” Richie approached Seth at the desk, keeping enough distance incase Seth went for a swing at him—which was an option still on the table. “She needs to feed. Kate won’t do it though. You need to convince her.”

He blew up at that, the rage seeping out all too quickly, hands flying out into the air as he yelled. “You’re the one who turned her into a monster against her will, you fucking convince her!”

Richie half turned like he was going to walk away, then changed his mind. “Would you have rather me let her die at the blood well, let her bleed out like an animal for slaughter?” he yelled back, trying to reason with Seth, trying to make it seem like he wasn’t the worst person in the world. “How would I explain that to you, huh? You’d never forgive me.”

The dark laugh came next. “Right. And I’ll forgive you for this?”

Richie straightened out his suit, seeing there wasn’t much else he could do to make the situation better. “Just talk to her. Okay? She’s come this far. She doesn’t need to die this time around.” As he turned his back once more, he added, “She trusts you.”

With that, he left and Seth was alone. The room felt like it was squeezing him in, sucking all the air out. Seth backed up until the desk stopped him, palms flattening against the cold metal for support before he lost all ability to stand.

He stayed like that for a long time.

The world as he knew it had ended.

—

When he banged lightly on the door to the bedroom, Seth was nervous. He hated that feeling to the core, but he hated himself even more at the moment.

The door swung open, the strands of her rich brunette hair blowing as it did, and time stopped for him when he put eyes on her. She looked exactly the same, flawless pale skin, warm eyes, youthful look, and that rendered him speechless. If he didn’t know any better, he would have thought that she was entirely human, the same as the last time he saw her.

He never expected any feeling of disgust to come up towards her like it did with the rest of the culebras. Kate was different and a different kind of feeling stirred in him after seeing her again after so much time apart.

After he had left her.

Abandoned her.

His hand at his side balled into a fist to keep himself grounded, before the insanity swooped in and snatched him up.

“Hi,” she said, Kate sounding defeated, tired, and lost.

He felt his face change from a stern one to a perplexed one. “Can I come in?”

She opened the door wider and stepped aside. Seth entered the room that had remained empty, decorated in a style that Kate would never like.

It would be a lie to say that he wasn’t uncomfortable. His hand rubbed the back of his neck, not sure how to even begin.

“Richie sent you?”

“Yeah.”

She rolled her eyes, shutting the room so they would be alone. He had spent months alone with her and yet he felt in that moment he felt so disconnected. Being alone with her felt unnatural.

“Sent you running after me to get me to _feed._ Well, I’m sorry you wasted your time but—”

Seth cut her off. “You just need to trust me.”

He was asking for a lot with that one. Kate felt the same.

“Trust you?” she laughed at him, the absurdity of this words sinking in. “I did trust you. I really did.”

Did.

Past tense, he noted. He didn’t blame her.

“You remember what you said to me in the hotel when you kidnapped me and my family? _You do what I tell you, when I tell you, and you’ll get out of this without any bumps or scrapes_ ,” she recalled. Kate moved so that she was in front of him, holding up her arms to showcase herself. “Well here I am, bumps, scrapes, and all.”

Seth hung his head, eyes fixated on the floor. “I know. I’m sorry. It’s my fault.”

“It’s not _your_ fault.”

“I shouldn’t have left you. This wouldn’t have happened.”

Kate huffed, unimpressed. “You shouldn’t have kidnapped me. That would have solved a lot more.”

He knew that all too well. Still, the words cut in deep and all he could say was, “I’m sorry.”

The suit jacket slid off his arms and landed on the bed next to him. Seth undid the buttons around the collar of his white dress shirt, sitting down on the edge. Offering up his neck to Kate seemed like a way to make things a little better, or at least a little more right. He would have to spend his entire life trying to make up from the things he had done to Kate, and he would never be able to get them to even ground.

“I can’t lose you again, Kate.” With a deep breath, he looked up to Kate, hand running over his neck. “Go to town,” he told her, ready for the bite.

She shook her head, eyes welling with tears, nearly breaking Seth in half from pain. “I can’t.”

“You can.”

“I don’t want to!” she clarified, voice cracking. “Especially not to you. I still care, you know, even if I don’t trust you entirely.”

“I don’t deserve for you to care about me, Kate.”

She reached out for him, hand gliding across her cheek. The warmth and softness of her hand made him almost lean into the embrace and let go of everything, but that would make him weak. He couldn’t afford that. His focus needed to remain of getting Kate fed.

“Do it. I’ll be fine,” he urged to her.

“I don’t even know how.”

The desperation in her voice hurt him like nothing else ever had. Seth was at the point where he was actively trying not to allow himself to get all teary eyed in front of Kate.

Before he could think it through, the switchblade he carried around with him was pulled from the suit pocket next to him and opened. Delicately, he nicked the corner of his neck, almost as if the blade to a razor had got him, although that time it was intentional. Her wide eyes were immediately drawn to the source, zeroing in on it like a hawk with prey.

He didn’t realize what it would trigger. Once second she was standing there before him delicately touching his face, the next she was on his lap, teeth sunken into his neck, on hand in his hair pulling. “Ahh,” he complained before grinding his teeth together to shut him up. He simply held her at the waist until she was done.

—

It became a regular thing after that—Kate feeding on him.

She hated it.

Seth didn’t mind so much anymore.

The twinge of pain from the fangs wasn’t so great but it helped Kate and that was all he cared about. Better him that some poor sucker off the street. Kate didn’t need to feel bad about it either. And at least he could time her hunger needs like clockwork.

On that particular night they were in the car driving back from a local shop after Kate picked out some clothes since she was tired of wearing the other female culebras items that were not at all something she would pick out for herself. They were almost back when Kate flipped the mirror on the visor back up loudly, drawing his attention.

“Something wrong?”

 Kate sighed, leaning back in the seat with her arms crossed. “I wish the part about vampires not seeing their reflection was true.”

She hated herself.

Seth could relate. Most days he hated himself too.

“Don’t be so hard on yourself,” he tried to advise.

“I’m not _myself._ I’m something else now.” She let her elbow rest on the middle console and put her head onto her palm. “I can’t walk in the sun, I can’t get through a week without putting holes in our neck, and I’ll never even be able to go to the beach again. I’m not myself.”

Seth was trying really hard to figure a way to make it seem like life was still worth living for her. It had proved to be a difficult task lately. “You can still go to the beach.” He thought about it and modified the answer. “Just at night. Think of it this way, no crowds. That’s a plus.”

“What fun,” she replied darkly, mood sour.

“Could be.” Seth tapped the steering wheel. “I’ll prove it to you. We could go right now.”

She made a doubtful face, sitting straight up again, but still intrigued. “The beach is like two hours away from here.”

“Kate, after all the time we’ve spent driving around in Mexico, do you really think that two hours would be a deterrent?”

“What if the sun comes up before we get back?”

Seth smirked, shaking his head. She would try and come up with any excuse just to challenge him. “Then we’ll rent a room somewhere until it’s dark again.”

“What if there’s nowhere around?”

“Then I’ll throw you in the trunk and drive back.” He looked over and threw her a smartass look. “Sound like plan?”

Kate rested her head onto his arm, nuzzling against him. “You don’t need to do this. I’m sure you’re tired.”

“I’m not tired. And, yes, I do need to do this,” he countered.

He’d do anything to make her happier.

“Thank you,” she whispered, the brush of her lips pressing onto his arm giving him a jolt to the heart. He played it off like it was nothing, but deep down he knew there was something changing.

—

Every touch after that, every finger stroke along his arm, every squeeze of his hand before she went back to her room, every brush of her nose on his neck after she fed, pushed him further towards her even if he tried to pull away emotionally.

He was getting in deep.

Too deep.

Seth’s feelings grew even though he tried to keep them caged away in the corner of him he didn’t allow anyone into. That would be dangerous from him, to be vulnerable.

Kate broke him down though, unconsciously working her way into his heart.

He would be empty without her.

—

“Seth?”

“Hmm?”

“If I asked you to stake me, would you?”

His voice was shallow when he replied, “No.”

She was unhappy some days, especially the ones where she had nothing to keep her occupied. Seth did his best to give her things to do but when he was away like he had been for the past two days, Kate usually remained behind. After he would get back was then when she would ask morbid questions like that. He made a mental note to start bringing her along even if Richie thought it was a bad idea. Leaving her alone was an even worse idea.

“Would you make me do it to myself then?”

“Please don’t make me think about it,” he pleaded, the idea hurting him too much to handle. “I can’t.”

It was a little glimpse into his feelings and Kate understood somehow. “Okay.”

She dropped the subject entirely and never mentioned it again. Seth still wondered how often she thought about it.

—

Seth started to watch her more closely. He saw she was happiest around him and he knew he was happiest around her. Simple math. She would spend most of her nights with him in his office until she lifted her arms up from the chair she was in, her nonverbal request for him to carry her to her room. He always obliged, picking her up bridal style as she held on tight, both of them blissfully ignoring the sideways glances from the others—mainly Richie.

When he would put her in her bed, a few times she held onto his hand longer than she should have and Seth never pulled away even though he should have too. They were trapped in this endless cycle of testing the limits.

One of them was bound to break.

Seth would bet it would be him.


	2. Surrender

He thought it might just be him who was feeling the sexual tension. The intensity was increasing with every day, every hour, every glance her way, every amount of skin contact. It was driving him insane. Even when she wasn’t around, Seth was thinking about her. Kate was like an addiction, one that Seth was losing the ability to resist.

One incident played out in the back of his mind a lot. There was one time a few weeks back where he got busy with shit and had to make her wait a few extra days to feed on him. It wasn’t an ideal situation, but there was nothing that he could do. Luckily, Kate was never pushy. She had patiently waited until the night came when she peeked into his office to say goodnight but he instead waved her in, telling her she shouldn’t have to wait any longer.

“I can wait,” she tried to argue. “It’s late. Losing blood can be taxing on the body.”

He shot her a look. Seth knew better. “Get over here, Kate. We both know I’ll be fine.”

She shut the door and tiptoed over to him as he pushed away from the desk in the chair. He loosened up the black tie and went for the first button on his usual dress shirt. Kate wedged herself in between his legs and took over, fingers unbuttoning his shirt for him, almost in a taunting way. She could disguise it pretty well, but Seth watched her eyes that were lustful for the blood.

Seth was lustful for something else—Kate’s body—as much as he would want to deny that.

His hands balled into fists before he pushed logic aside and gripped her waist, moving her so she could get on his lap. He expected her to go straight for the neck but she lingered in front of his face, the edges of her hair stands touching his chest. She was so close to him that for a second there he almost grabbed her face and kissed her. But if he had done that though, he would have also planted her on the desk and stripped off her clothes and lost himself inside her.

Shit.

He really needed to learn how to shut his brain off until he was alone.

In an effort to move things along quicker, pulled her in closer, shutting his eyes, hand slipping a little too low along her backside. Kate tilted his head to the side. She bit in gently, but sucked hard, a few drops of blood falling down his neck, leaving a red trail. He was surprised when he felt her tongue press against where the blood was so no trace was left behind. He gritted his teeth together so a moan wouldn’t come out his mouth uninvited, praying that Kate didn’t notice how he was getting hard. Never in his wildest dreams would he have imagined that Kate drinking his blood would be a turn on.

Seth would later eventually cave in and jerk off in the shower, remembering how Kate’s tongue felt on his skin, and coming way to easily at the thought her on top of him. Perhaps he should have felt ashamed, but there was no more room in his mind to force the feeling.

—

When an angry culebra showed up to their doors, shit went down and Seth ended up with a bullet in his abdomen. By some fucking miracle, it has whizzed by all the important organs and only rendered him in a lot of pain and a pissed off mood. But at least the fucker who shot him was ashes.

He had gotten all stitched up and was trying to sleep off the pain unsuccessfully when the door to his room opened and Kate swiftly entered. “You doing okay?”

He cringed at how it must look from where she stood. Poor Seth, all banged up from one bullet. “Better now that you’re here.”

Kate giggled. “What a line,” she complained. “Say that to all the girls?”

“I’d like to think I’m smoother than that.”

Her eyelashes fluttered, smile being the best pain medication anyone could ever receive. “You _are_. It’s annoying.” Kate laid down next to him, moving slowly so she would disturb the mattress too much. “Looks like you’re the fragile one now,” she teased, grin a little too wide for him not to smile back.

“You’re hilarious, Kate. _Fragile_. Thanks for the compliment.”

“It’s true,” she reminded him. “Out of everyone here, you’re the only human. You’re the weakest.”

She was pushing his buttons. They knew how to do that to each other all too well. “Oh, is that so?” he countered, pretending to be offended.

She put her hand over the left side of his stomach where the bullet had gone into and he grimaced from the slight twinge of pain from the little bit of pressure. “Yes, it is.”

Maybe there was some truth to it after all.

“Okay, point taken.” Unconsciously, Seth grabbed her hand and pulled up to his chest. She flattened her fingers against him and snuggled in, nose rubbing his jawline in a tender show of affection. Somewhere along the way the closeness between them felt natural again. “I may be the only human here but I worry about you like you’re still human,” he mentioned. “All the time.”

She was quiet for a minute, thoughtfully examining his words. “I like that you worry. Means you care.”

It was interesting. Kate was only supposed to be a means of getting across the border, a loose end never tied up once they left the Twister. Luckily the two actually made it out of that place in one piece. Then something very different from the original plan went down. He ended up in the position where every move he made was dictated by his feelings for his one girl.

And the feelings…they overwhelmed.

“I never thought you cared that much about me,” she elaborated further after Seth had gotten lost in thought and never responded. “At least not during our Mexican honeymoon.”

His brows pulled together in confusion. “Mexican honeymoon?”

“That’s what Richie called it,” she clarified, adding a small laugh to the end. “Though now that I think about it, less eyebrows may have been raised if we had worn some rings and claimed to be newlyweds. But, no point in dwelling over the past, right?”

He side-eyed her. “This mean you forgive Richie about the whole turning you thing?”

Kate’s face went stone cold in an instant. “ _Some_ things you can’t forgive. At least not in the near future.”

“Will you ever forgive me for leaving you back in Mexico?” he asked, almost as a form of punishment on himself because he wanted her to say no.

Kate, however, was one to always carefully consider those in her good graces. She picked her head up, cupped one side of his face, and kissed him on the forehead lightly. “You’re already forgiven. Stop thinking about it.”

He shook his head against the pillow. “You’re too good to me, Kate.”

“I said stop thinking about it,” she said sharply again, not pleased to be repeating herself. “It’s water under the bridge with us, deal?”

Despite the hesitance, he agreed. “Deal.”

Kate loosened her hand from where it had rested on his arm and let it drift down to the edge of his white tank top, pulling it up to right above where his ribs ended. “Does it hurt a lot?”

He glanced down at the large white bandage adhered to his skin, curtesy of the nearest hospital. “Truth?”

She nodded.

“Hurts like hell.”

“I was just kidding about you being fragile,” Kate lightly added.

“Kind of am, especially in comparison,” he allowed, only because it was Kate who had mentioned the obvious weakness.

Kate pulled his shirt back down, smoothing it out. “In that case, I’ll be careful with you then.”

He chuckled to himself. “Please do.”

They were silent for a while until Kate drew in a breath, then released it quickly, Seth feeling it across his chest when she put her head back on his arm. “You could have died today.” There was a mix of sadness and anger in her voice, though she kept it soft.  

“I know.”

Kate sniffled, then moved her head so she was resting it fully on his chest, Seth looping an arm around her. She started to draw circles along his shoulder blade wither nail in a way that made him feel like closing his eyes and drifting off to sleep. “I was scared.”

“Me too,” he admitted.

The truth was so simple with her.

“Want me to leave so you can sleep?”

He answered immediately. “No. Stay.”

—

Seth had her pinned in between him and the wall, though Kate could easily maneuver around him to get away. His forehead was touching hers, palms flattened onto the sides of her head, hair intertwined between his fingers. She was having another bad day and Seth couldn’t stand seeing her miserable and trying to bottle it up. He had spent his whole life doing that and it for sure never did anyone any good.

“What’s bothering you?” he muttered, wanting to know how to fix things.

She blinked, eyelashes slowly closing and opening. “I feel alone. All I have is Scott and he’s rarely around,” she said calmly, frown deepening.

“You have me too,” he breathed, trying to reinforce their unusual bond.

She was silent for a long time until her voice broke and told him, “One day you’ll die. What am I supposed to do then? I can’t stop thinking about that, losing you.”

It was a hard pill to swallow—not the dying part, the leaving her behind part. All Seth ever expected was to die someday, but Kate complicated that in a way he hadn’t anticipated. Now all he could think of was how it didn’t seem so bad to have fangs and drink blood if it meant being around Kate for the rest of eternity. All of a sudden, the months of Richie slyly trying to convince him to become like him was bouncing around in his mind. But, boy, would he be pissed if he knew that Kate was the reason behind it if he ever changed.

Kate’s hands ran up underneath his suit jacket, pressing against his side, pulling him even closer. “I’ll probably walk into the sun the day you die, Seth.”

Another dagger to the heart.

His nails dug into his skin and Seth let out a groan that sounded like a mix of pain and pleasure. Kate was stronger than she used to be.

“Don’t say that.”

“Then answer me this,” she demanded, nose brushing against his cheek. “What do I do when you’re gone?”

Seth drew in a sharp breath, countered by a long exhale. “Maybe I don’t have to go.” The words sounded wrong to his head but his heart was egging him on to keep going. “We can be like this for a long time.”

“I won’t let you chose this life just for my sake.”

His lips pressed against her neck, his wants and needs taking over. “I think fate already chose it for me.”

“Seth,” she breathed out. Kate grabbed ahold of his bottom lip with both of hers and pressed into him. Everything fell into place after that.

“Kate…”

He picked her up and pushed her against the wall in their dark corner of the hallway. Her legs looped around his waist effortlessly as he hoisted her up enough to press his groin into her, pulling up the black skirt she was wearing. The feeling of his hands running along the smooth skin until it hit lace was enough to send desire signals firing off inside him like fireworks.

With her securely at his waist, one hand snaked up her stomach, underneath her bra, and squeezed her breast. The resulting gasp from Kate made him moan into her neck, slow movements of his hips against hers making him hard.

“I want you,” she whispered into his ear, voice seductive and hard to resist as she nipped at his ear. “I want you right now, right here.”

He was undoing his pants before he had a chance to process anything, pulling them down just enough to get his dick out. The pocket knife from his suit was grabbed before he let the jacket fall to the ground. He opened the blade and slit her underwear off from the sides of her hip, too far gone to have the patience to put her down and take them off normally.

His mouth was on hers, almost in a sloppy way. Too uncoordinated, fueled by the ache in him that needed her. In the brief second that they made eye contact when he extracted his mouth off of hers, he realized how bad she wanted him after all—which was just as much as he wanted her, with pupils blown up wide as they could with hunger for each other.

When he reached between them to guide himself into her, Kate straightened her back against the wall and arched for better access. Seth wanted to savor the moment when he felt how hot and wet she was once his tip was enveloped around her but he was too impatient. His hands allowed her to slip downward onto him completely, Kate wiggling to adjust, her thighs tightening around him.

Seth’s jaw tightened, the sensation too good for it to last long.

If he had started slow, he certainly hadn’t kept with that pace. His hips began to desperately pound against her, her head bumping the wall without care, sloppy and uncoordinated kisses placed everywhere he could get his mouth on. “ _Fuck_ ,” he murmured somewhere in between their wall sex session, “you feel so good, Kate.”

He needed it, needed it so badly.

Deep inside he could feel everything building up, the more he slipped in and out of Kate, the more his mind went out the window and all rational thought seized. That was his only reason for why he said, “Bite me.” He knew by the way her hands gripped onto him that she wanted to. “Do it,” he groaned, nearly breathless, on the brink of losing it.

When the two sharp needles pricked into his neck, the same spot as usual, he jerked into her again, harder that time. Blood was intoxicating for her, and with the blood in her system, Kate was so easy to please that when her walls tightened up around him and she moaned his name, Seth lost it all and gave it one more good thrust before he was spilling into her.

Seth plastered his mouth shut on her shoulder so the sound that was trying to force its way out wasn’t heard by everyone lingering about. Kate slumped forward slightly, a small content sigh escaping from her. Seth unwillingly let her back onto the ground, pulling her skirt back into its place, and fastened his pants again.

Her thumb ran over the spot where she had bit into, the area still tender. She had the look of guilt in her eyes, the fixation on the two little puncture wounds making her feel that way. Before she could apologize, her cupped her face and kissed her, even despite the blood coloring her lips.  

He might have even added a proclamation of love into the mix.

—

They ended up having sex a lot, in one way or another.

(He obviously enjoyed that factor of their relationship a lot)

Sometimes Seth was sitting at his desk and Kate is underneath him, knees on the floor with her mouth around his dick until he grabbed a fistful of her hair and climaxed (sometimes, even when someone walked in unannounced—mainly Richie—and he had to pretend that Kate’s tongue wasn’t running along his shaft until his brother was gone and Kate giggled under the desk).

Sometimes he had her on the bed with his face between her legs and it was her who was grabbing his hair as she writhed around.

Sometimes he had her face down and bent over the side of a table and sometimes she was straddled to his lap in the driver’s seat of a random car in the middle of nowhere, just fucking him hard until they were both overwhelmingly satisfied.

Life couldn’t get much better.

—

“Let me get this straight,” Richie announced, face portraying that he wasn’t totally computing things. “You give me shit about being a monster, but here you are cozying up to Kate, who by the way is exactly like me?”

“It’s different, Richard,” he defended himself, throwing his brother a _leave me the fuck alone look_.

“Different?” He looked amused by that. “So it’s okay to have her drink your blood as long as you’re getting your dick sucked on the side? Is that how it works?”

“Don’t be a dumbass, Richie,” he remarked. “You know that’s not true. It has nothing to do with sex. It’s not some sort of weird agreement where I give her blood and she repays me with sexual favors.”

Ugh.

It sounded worse saying it out loud.

“You really fucking think that?”

“No.” Richie’s face softened, lightening up around the edges. “Just don’t fuck it up, whatever it is you two having going on.”

“I’m not planning on it.”

“Good.”

—

There was one night where he was lying in bed with Kate wrapped in his arms, him breathing in her hair, and he was listening to the sound of her steady breathing. For the first time in a long time, Seth felt like everything was good in his life, despite there actually being major flaws. But having Kate meant that there was something to look forward to in the morning—seeing her smile and her sleepy eyes flutter open.

In the beginning, he had tried to convince her there was something to live for even if she was a culebra, and it turned out that she was the reason that he had a reason to live.

Funny how things worked out like that.

Seth nuzzled into the back of her neck and drifted off.

—

A few years later and he told her to turn him before he got too fucking old. She initially refused, saying it wasn’t right, but he convinced her eventually, promising a life together away.

She did it, finally, and they continued on into eternity by the beach.

**Author's Note:**

> The good stuff comes in part 2 (wink, wink)


End file.
